Question: Which of these numbers is composite? ${33,\ 41,\ 67,\ 79,\ 89}$
Answer: A composite number is a number that has more than two factors (including 1 and itself). 41, 67, 79, and 89 each have only two factors. The factors of 33 are 1, 3, 11, and 33. Thus, 33 is the composite number.